Orig. a craftsman who made chests, usually covered with leather. These chests in time gave their name to the post of the officer who kept money in them, i.e. a cofferer. One of the treasurers of the royal *household; he ranked third in the hierarchy of the *king's wardrobe. The title was also borne by an officer of the *Green Cloth. [< Lat. cofferarius = cofferer]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.